[1]宋建民,孙爱友,魏东芝.融合型乳酸片球菌素在大肠杆菌中的表达与纯化[J].南京理工大学学报(自然科学版),2011,(02):268-272. SONG Jian-min,SUN Ai-you,WEI Dong-zhi.Expression and Purification of Fusion-typed Pediocin PA-1 in Escherichia Coli[J].Journal of Nanjing University of Science and Technology,2011,(02):268-272.

To effectively express pediocin PA-1(PED)in Escherichia coli,the primers specific for PED coding sequence is designed and synthesized according to the National Center for Biotechnology Information.The gene fragment of PED is amplified from genomic DNA of pediococcus acidilacticii LH31 by polymeras chain reaction.The plasmid pET32c-PED,encoding PED fused with His-tagged thioredoxin protein,is constructed and introduced into escherichia coli BL21(DE3)strain.The fusion protein is expressed in inclusion bodies counting 28% of total cellular proteins in the strain after induction of isopropyl-β-D-thiogalactopyranoside(IPTG)and purified by nickel-nitrilotriacetic acid(Ni-NTA)metal affinity chromatography.For the recovery of biologically active PED,the purified fusion protein is cleaved by enterokinase and the liberated PED is finally purified by ultrafiltration with a 78% yield.The fusion protein,which does not have bactericidal activity against enterococcus faecalis,is cleaved by enterokinase and the cleaved PED recovers its own bactericidal activity.